Dispensers find numerous uses both domestically and industrially for dispensing a variety of fluids. There are many different types of dispensers with one of the more popular liquid dispensers being a spray bottle. Spray bottles dispense a variety of fluids from plain liquids, such as water, alcohol, to complex liquid based compounds. Cleaning products, such as kitchen and bathroom cleaning products, are often dispensed through spray bottles.
Traditional spray bottles contain a single reservoir that holds a single fluid and include a spray bottle head that is actuated to dispense the fluid. The spray bottle head is typically made up of only a few parts including a trigger lever which activates a small pump. This pump is attached to a plastic tube that draws the fluid from the bottom of the reservoir (which can be in the form of a plastic bottle). The pump forces the liquid down a narrow barrel and out of a small hole formed in a nozzle piece, which is often adjustable to change the flow characteristics of the fluid. The fluid pump has a simple design in that the main moving element is a piston that is housed within a cylinder. Inside of this cylinder is a small spring. To operate the pump, the user pulls back the trigger which results in the piston being pushed into the cylinder. The moving piston compresses the spring so that when the user releases the trigger, the piston is pushed back out of the cylinder. These two strokes of the piston constitute the entire pump cycle.
The downstroke of the piston when the piston is pushed into the cylinder reduces the area of the cylinder and therefore, forces fluid out of the pump. Conversely, during the upstroke of the piston, the area within the cylinder is expanded and fluid is drawn into the cylinder. In order to accomplish the aforementioned actions, the spray bottle includes a one-way valve and more specifically, includes typically at least two one-way valves. The spray bottle can have two one-way valves in the pumping system, namely, a first one-way valve that is located between the pump and the reservoir and a second one-way valve that is located between the pump and the nozzle. Often, the one-way valve between the pump and the reservoir is in the form of a small rubber ball (or metal or plastic) that rests neatly inside a small seal. When no pumping action is occurring, the ball seats against the seal and the fluid passageway is blocked. During a pumping action when the user releases the trigger, the expanding area of the cylinder sucks the fluid below resulting in the ball being pulled out of the seal. Since the ball is not seated against the seal, the fluid is free to flow from the reservoir. However, when the trigger is squeezed, the dispensing force of expelling the fluid pushes the ball into the seat blocking off the passageway to the reservoir and as a result, the pressurized fluid is pushed only into the barrel.
The second one-way valve can be in the form of a cup-shaped structure that is located between the pump and the nozzle and fits over one end of the barrel. On the upstroke, the inward pressure of the pump pulls the cup against the barrel, thereby preventing air from flowing through the nozzle. Conversely, on the downstroke, the fluid pushing out lifts the cup off of the barrel slightly and flows on through the nozzle. Without this second one-way valve, the pump system would not be able to draw fluid up from the reservoir since this requires negative pressure (i.e., a drop in air pressure). With no one-way valve, the upstroke would not lower the air pressure in the pump. In many spray bottles, this second one-way valve also acts as a shut-off system in that when the nozzle piece is rotated (so as to screw the piece inward), the second one-way valve is pushed against the barrel and thereby, preventing any liquid from being forced out.
While there are multi-reservoir spray bottles in the prior art, most of these products are susceptible to fluid contamination in that the multiple reservoirs connect to a common part in the spray head in which comingling of the fluids can occur prior to discharge of the fluid. This is completely undesirable in many settings. For example, if one reservoir holds bleach and the other reservoir holds water, it is clearly not desirable and can be dangerous to dispense water that is contaminated with bleach residue. There is therefore, a need for a multi-reservoir dispenser, such as a spray bottle, that has completely separate plumbing for each fluid to be dispensed along the entire flow path from the reservoir to the nozzle.